In this lab, the pH of flat sprite and a fresh sprite are compared two ways: one way was to record the pH directly with a digital pH probe and the other was to calculate the concentration through titration. Because the reaction is a neutralization reaction, the concentration of can be calculated if the concentration of is known. At the end of the titration, the moles of will equal the moles of and the pH is expected to be greater than 7 because the found in sprite is weak and is a strong base. The pH of both the fresh sprite as well as the flat sprite were measured with a pH probe before any titration for comparison.

The initial pH of the flat sprite was higher because had bubbled out and when dissolves in the sprite, it makes . Therefore, controls the pH by introducing extra into the solution. However, this is not the primary acid in sprite. The primary acid is . , which is found in sprite, buffers the solution. Therefore, Sprite is a buffer. The titration removes all including those produced by and . Therefore, at the neutralization point, there are no remaining. We would expect the calculated pH of the titrated sprit to be higher because there are no more remaining ions. The difference between flat and fresh sprite is that the fresh sprite has more in it. This is because ionizes to a small percentage, producing ions. This lowers the pH as well as . The pH of the flat and fresh sprite were not exactly the same but very close to each other. The reason is because the solution is buffered. Any ions produced by the bubbles in sprite are consumed by as shown in the equation . Overall, Sprite along with probably majority of soft drinks, are buffered because they are being ingested and the body is sensitive to changes in pH. The pH of Sprite is between 3 and 4 while the pH of water is 7. A pH of 3 is 10,000 times more acidic than a pH of 7. While the weak acids found in sprite produce small amounts of , the titration...

YOU MAY ALSO FIND THESE DOCUMENTS HELPFUL

...small amount of energy to increase their temperature. On the other hand, insulating substances, such as the plastic foam in coffee cups, require a large amount of energy to increase their temperatures. Anyways, the equation used to figure out energy needed to increase temperature is:
Q (Heat Energy) = mass x Specific heat x Change in Temperature
To determine the specific heat with the use of a calorimeter , the equation is :
QSubstance = -[ Qwater + QCalorimeter] which translates into
(mcΔT)Substance = - [(mcΔT)Water + (CΔT)Calorimeter]
Materials:
Coffee-cup calorimeter
Water
Safety Goggles
Thermometer
Lab Apron
Ringstand
Tongs
Clamp
Graduated Cylinder
Test tube
Unknown Metal Sample
Hotplate
Triple Beam Balance (or other mass measuring equipment)
600 ml Beaker
Procedure:
1. Follow all safety guidelines prior to starting. Clear lab station. Gather all materials.
2. Set up the coffee-cup calorimeter as shown in the previous experiment in Figure 17-1.
3. Pour 75 ml, with a graduated cylinder, of cold water into the calorimeter and then cover the calorimeter.
4. Weigh out about 30 g of the unknown metal sample and record its identification number.
5. Pour 450 ml of water in a 600 ml beaker. Clamp the beaker onto a ringstand, place the hot plate underneath the beaker, and heat the water to boiling.
6. Transfer the metal sample to a clean, dry test tube and place it in the boiling water bath and let it stay there...

...INTRODUCTION:
The purpose of this experiment is to measure the formation constant of the tetraamminecopper(II) ion by colorimetry. Anhydrous copper sulfate (CuSO4) is white, which means that it does not absorb light in the visible region of the spectrum. The hydrated copper sulfate (CuSO4 - 5H2O) is blue. The structure of the compound can be represented more accurately as Cu(H2O)4 SO4 - H2O where four water molecules are bound to the copper ion and the fifth is a water of crystallization. The water molecules are arranged at the corners of a square, with the copper at the center. Such an arrangement is called square coplanar. The oxygen of each water molecule shares one pair of electrons with the central copper ion. The absorption spectrum of 0.01M copper sulfate is shown, in Figure 1, by the dotted line, A. Absorbance is plotted against wavelength in angstroms (Å). Notice that the compound absorbs light of wavelengths from 6000 to above 8000 Å, which is the yellow-to-red region of the visible spectrum. The light transmitted through the solution comes out richer in light of blue wavelengths (4000 to 5000 Å) than white light, and so the solution looks blue.
When ammonia is added to a solution of copper(II) cation, a deep blue color is formed immediately. The blue color is due to the complex. ion Cu(NH3)42+.
Cu(H2O)42+ + 4NH3  Cu(NH3)42+ + 4H2O
This complex ion, the tetraamminecopper(II) cation, has a square co-planar geometry also. The absorption...

...﻿
4/2/14
Period: 1st
Chemistry
Sour Acids and Bitter Bases
Purpose:
The purpose of this lab was to observe the different reactions formed between various acids and bases with the aid of indicators.
Equipment:
1. Safety goggles.
2. Droppers.
3. Red Litmus paper.
4. Blue Litmus paper.
5. pH paper.
6. Well plate.
7. Micro spatula.
Materials:
1. Zinc.
2. Magnesium.
3. Iron.
4. Copper.
5. HCL.
6. HC₂H₃O₂.
7. NaOH.
8. Phenolphthalein.
Procedure:
Part A:
1. Add five drops of HCL, HC₂H₃O₂, and NaOH to different depressions in the well plate.
2. Place a drop of each solution onto a piece of red litmus paper and record
observations.
3. Place a drop of each solution onto a piece of blue litmus paper and record
observations.
4. Place a drop of each solution onto a piece of pH paper and record observations
5. Add one drop of Phenolphthalein to each solution and record observations.
Procedure continued:
Part B:
6. After the well plate is cleaned, add a piece of zinc, magnesium, iron, and copper to
four separate depressions in the well plate.
7. To each depression add enough HCL to cover the metals. Observe and record results.
8. Clean the well plate and place the same metals in four separate depressions and add
enough HC₂H₃O₂ to cover the metal. Observe and record results.
Observations:
DATA TABLE 1 Reactions with Indicators
Solution
Red litmus
Blue litmus...

...﻿Laboratory 6: Energy Changes in Chemical Reactions
Note: Lab reports are to be completed by each student individually and in their own words
Observations: (This part is to be completed in class)
Part 1: Physical Change- Heat of Solution for Sodium hydroxide (NaOH)
3.2 grams NaOH
Result:
Temperature of DI water = ____22.8 °C
Temperature after addition of NaOH = ______31.8 °C
Part 2: Chemical Change- Reaction between acid and base
Result:
Temperature of HCl = ___21.4 °C
Temperature after addition of pellets of NaOH = ____26.4 °C
Part 3: Chemical Change- Reaction between stomach acid and antacid
Result:
Temperature of HCl = __23.3 °C
Temperature after addition of Tums = __18.5 °C
Questions and Conclusions:
This part (everything below) is to be completed by each student individually in their own words. Plagiarism or copying will be penalized.
Part 4: General Concepts- Define the following Terms
Exothermic Reaction: are chemical reactions that are letting go energy with heat, light, or sound are impulsive.
Endothermic Reaction: chemical reactions that have to take in energy in order to work and are not impulsive.
First Law of Thermodynamics: basically means matter or energy can not be created or destroyed. The universe is energy endless, it can be changed, moved, controlled, stored, or dissolute.
Second Law of Thermodynamics: Increased Entropy; the quality of matter and energy declines progressively over time.
Part 5. Answer the following...

...﻿Name: Cora Wilke April 19, 2015
Laboratory 7: Building models of Biological MacromoleculesQuestions:
1. Which functional groups are involved in buiding a covalent bond between these amino acids?
Amine and Carboxylic acid = Amide
2. When the covalent bond is built between alanine and glycine, which functional group will alanine use for peptide bond?
Carboxylic Acid
3. When the covalent bond is built between alanine and glycine, which functional group will glycine use for peptide bond?
Amine
4. When the covalent bond is built between glycine and alanine, which functional group will alanine use for peptide bond?
Carboxylic Acid; the NOOH group of forms the peptide bond.
5. When the covalent bond is built between glycine and alanine, which functional group will glycine use for peptide bond?
Amine
Part 2: Fat.
Questions:
6. Which functional group will be given by glycerol? OH Group (alcohol)
7. Which functional group will be given by butyric acid? Carboxylic Acid
8. What is a difference between fatty acids found in fats and oils? Saturated fats are solid (butter)
Unsaturated fats are liquid (olive oil) and are double bonded
9.
Part 4: Carbohydrates.
Questions:
1. Which functional groups are involved making the glycosidic bond? Alcohol
2. How many sugars are contained in a disaccharide? Give example of a disaccharide. Two Sucrose (Maltose)
3.
4. Complete the table below (Table 1).
Table 1:
Number
Name of the Carbohydrate
Names of component sugars
Source...

...﻿Laboratory 3: Molarity Of Saline Solution
Data: Please write your observations about the appearance of the solution.
1. Normal Saline- The solution appeared clear at the start with slight particles showing, once adding the salt it still appeared clear.
2. Nasal Irrigation Saline- Solution appeared cloudy once adding the salt and baking soda, then it turned semi-clear about 30 secs later; it was more concentrated than the normal saline.
Results:
1. Determine the molar mass of NaCl. Show the workup.
Na= 23g/mole Cl= 35g/mole
Molar mass of NaCl 23g/mole+35g/mole= 58g/mole
2. Determine the molarity of the two solutions you prepared in terms of NaCl. Show the workup.
Normal Saline
M=Mole/L of NaCl
Mass= .9g NaCl
.9g=1mole/58g= .015 moles/L
Nasal Irrigation Saline
M=Mole/L
1.23g=1mole NaCl/58g= 71.34 moles/L
3. The University of Wisconsin recommends that if stinging or burning occurs, than individuals should cut the amount of salt in half for the solution and decrease frequency of use to every other day. How does that affect the concentration of the solution?
When salt is decreased the concentration of the solution measured will also be decreased. This would also decrease the burning and stinging. When the solution is decreased to every other day it could prevent acidosis.
4. Compare and contrast the solutions in terms of their sterility and potential uses.
Both solutions must be sterile because both could be put into a human body. Normal Saline is used in an...

...﻿
Flame Test Lab
Morgan
Chemistry CP
5/30/14
Abstract-
In the flame test lab, the flame test was performed to excite the electrons in the samples and observe the color of the flame. The flame emits a color because each element has an exactly defined emission spectrum, which one can use to identify them. For example, NaCl was highlighter yellow, Sr(NO3)2 was sun orange, CuCl2 was turquoise, LiCl was neon red, KCl was solar flare yellow, and BaCl2 was Voldemort green.
Introduction-
In Bohr’s model of the atom, electrons travel around the nucleus in an orbit. The concentric circles in his model represent the energy levels. Electrons can jump from energy level to energy level and absorb or emit light energy when they jump from one energy level to another.1 By placing compounds into a flame, electrons can be induced to absorb energy and jump to an excited energy state. The electrons then return to their ground state by emitting a photon of light. The amount of energy in the photon determines its color; red for the lowest energy of visible light, increasing energy through the rainbow of orange, yellow, green, blue, indigo, and finally violet for the highest energy of visible light. Photons outside the visible spectrum may also be emitted, but cannot be seen. One can view the emission spectrum of colors all at once with the naked eye. It will appear to be one color, which is carefully described.
A flame test is a...